Depth-resolved elemental and molecular analysis of polymeric multilayers with EI-MS and ICP-OES using chemometric evaluation

Abstract

Polymeric composite materials with layered structures have increasingly gained importance as, for specific applications, the required properties cannot be achieved with one single material; thus, for example, multi-layer polymers or special surface coatings are employed.None of the conventionally available techniques enables a comprehensive characterization of composite materials, including depth-resolved information about their organic and elemental constituents.In this work, a previously introduced approach enabling the direct characterization of the organic and inorganic constituents of solid polymer samples was further developed and optimized for depth profiling analysis of stacked layer polymers. For this purpose, the ablation chamber’s washout behavior and transfer line’s transport efficiency were improved. Chemometric methods were applied for the data analysis to gain greater insight and enable more precise differentiation, comparison and classification.The work investigates the feasibility of the developed approach by analyzing a multi-layer stacked polymer sample created from nail polishes and using cluster analysis on the data collected with the bimodal detection. The layers of the sample could be differentiated by their organic and elemental constituents’ fingerprints, achieving a depth resolution of 7 µm.